Full wave, three-phase rectifiers are employed in a variety of environments. Depending upon the specific environment in which they are used, various requirements attend the construction of the rectifier.
One application in which such rectifiers is used is a so-called "brushless generator". In a typical brushless generator construction, three-phase windings forming part of an exciter are carried by the rotor. Rotor rotation results in the generation, in such windings, of a three-phase signal. Such signal then is rectified by a rectifier carried by the rotor to provide a source of direct current to the main field winding of the generator which also is carried by the rotor. Because the rectifier forms part of the rotor, it must be capable of withstanding the high centrifugal forces placed upon its components during generator operation. It also is highly desirable that the rectifier be as compact as possible, both axially and radially, so that the overall size of the rotor can be made as small as possible. An example of such an application is shown in U.S. Pat. No. 4,482,827 to Baldwin, dated Nov. 13, 1984 and assigned to the assignee of this invention. This patent shows six diodes each having a base forming one pole of the electrical circuit of the diode and a terminal forming the other pole of the electrical circuit. Such assemblies often are called discrete diode assemblies.
Another application of a compact full wave rectifier assembly for use in a brushless alternator is shown in U.S. Pat. No. 4,581,695 to Hoppe, dated Apr. 8, 1986 and assigned to the assignee of this invention. This patent shows silicon wafers (diodes) or chips which have a somewhat different physical mounting.
U.S. Pat. No. 4,329,603 to Ballard, dated May 11, 1982 and assigned to the assignee of this invention shows a further construction of a rectifier assembly for use on the rotor of a synchronous machine such as a brushless alternating current generator or a brushless synchronous motor. This patent shows an assembly which is mounted to a housing, insulated from a mounting base, capable of withstanding centrifugal force created at normal operating speeds and is efficiently cooled. The rectifier assembly can be connected to provide either half-wave or full-wave rectification.
The present invention is directed to further improvements in discrete diode assemblies of the character described above, such as for use in an electrical generator system utilizing an integrated diode rectifier, wherein the rotating discrete diode rectifier assembly is employed as a back-up. The invention includes such improvements as mounting the discrete diode in a non-conductive housing, the housing itself being mounted within the rotor of the synchronous rotary electric machine and providing for the passage therethrough of a coolant. The mounting plates for the diodes form part of the circuit, as heat sinks, to eliminate considerable wiring and its space requirements. The diodes are electrically coupled directly to their respective mounting plates. This is easily afforded by making the housing non-conductive.